Early Proterozoic (2.04 GA) phosphorites of Pechenga Greenstone Belt and their origin
Early Proterozoic (2.04 GA) phosphorites of Pechenga Greenstone Belt and their origin
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佩琴加绿岩带早元古代（2.04 GA）磷矿及其成因
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
R. Hoover
中科院分区：
文献类型：
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作者：
A. Y. Rozanov;M. Astafieva;R. Hoover
寒武纪和古生代的微体化石与2000 Ma的磷块岩没有发现主要差异。许多样品揭示了不同的微生物微观结构解释为蓝藻垫组成的丝状（直径1-3 μm，长度20 μm），球形（0.8-1.0 μm）和椭圆形或杆状微体化石（直径0.8 μm，长约2 μm），形态上分别类似于现代的微鞘藻属、管藻属、硫壳藻属和杆皮藻属，报告来自碱性或盐水环境。古元古代早期事件的序列表明水圈的显著氧化，包括磷块岩的形成和磷循环的变化，这与新元古代-寒武纪过渡期重复的序列相似，意味着陆地大气-水圈系统的氧化经历了一个不规则的循环发展。
No principal differences have been found between microfossils described from Cambrian and Phanerozoic and the 2000 Ma phosphorites. Numerous samples revealed diverse microbial microstructures interpreted as cyanobacterial mats consisting of filamentous (1-3 μm in diameter, 20 μm in length), coccoidal (0.8-1.0 μm) and ellipsoidal or rod-shaped microfossils (0.8 μm in diameter, around 2 μm in length) which morphologically resemble modern Microcoleus and Siphonophycus, Thiocapsa, and Rhabdoderma, respectively, reported from alkaline or saline environments. The sequence of the early Palaeoproterozoic events which point to a significant oxidation of the hydrosphere, including the formation of phosphorites and changes in the phosphorous cycle, mimics the sequence which was repeated at the Neoproterozoic-Cambrian transition, implying that oxidation of the terrestrial atmosphere-hydrosphere system experienced an irregular cyclic development.